Hypodermic injector including a needle guide with pain desensitizing means



C- W. HILL Sept. 3, 1968 HYPODERMIC INJECTOR INCLUDING A NEEDLE GUI WITH PAIN DESENSITIZING MEANS 2 Sheets-Sheet 1 Filed Oct. 23, 1965 ulllllllliilllhimhllllllil mmmm mgwm FIG. 2

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Sept. 3, 1968 C. W. HILL HYPODERMIC INJECTOR INCLUDING A NEEDLE GUIDE Filed 001.. 23, 1965 WITH PAIN DESENSITIZING MEANS 2 Sheets-Sheet 2 SG '-l4 FIG.6

INVENTOR. CLIFFORD W-HILL' MAJ/M9 United States Patent ABSTRACT OF THE DISCLOSURE Hypodermic injector of simple construction having an abutment of heat absorptive material, to be refrigerated and then placed on the patient to desensitize the area contacted by the abutmentagainst the pain of the needleand to guide the needle into the patients body.

This invention relates to hypodermic injectors, and more particularly, to such devices used with hypodermic syringes and hypodermic needles.

Prior to the present invention, there has been a long existing need for a means to minimize the discomfort resulting from injection of a hypodermic needle into the body of a patient. This need has been particularly 3,399,675 Patented Sept. 3, 1968 forms the abutment 18, and the end of the groove, 22 forms the needle aperture 20.

In operation, the abutment 18 or preferably the entire injector is cooled below ambient temperature by being placed in a refrigerator or freezer or by other suitable means. The injector is then placed on the patient at the desired injection site with the patient contacting abutment engaging the body of the patient. The patient then grasps the filled and sterilized syringe, preferably at. the flange and/or the adjacent principal outside diameter of the barrel 10, and inserts the barrel 10, with the needle 12 thereon, on through the inside diameter of the guide 16 until the needle 12 is inserted into the body of the patient to the desired depth. There is a reduction of pain when the needle is inserted into the body of the patient a due to the cooling effect of the injector. The groove 22 important for the many patients, such as diabetics, who

wish to or must self-administer the required medicaments, such as insulin, by means of a hypodermic. Some diabetics, for example, refuse to take or delay taking the prescribed dosage of insulin for fear of the pain or discomfort resulting from injection of a hypodermic needle into the body.

The main object of the present invention is to minimize the pain or discomfort resulting from the injection of a hypodermic needle into the body of a patient.

Other objects are to provide a hypodermic syringe injector which is safe to use and is easily usedby anyone regardless of mechanical aptitude, and to provide an inexpensive hypodermic syringe injector which can be manufactured with inexpensive tooling.

In the drawings:

FIGURE 1 is a front elevation of the preferred embodiment of the invention, as employing a hypodermic syringe and a hypodermic needle;

FIGURE2 is similar to FIG. l, except with the syringe and needle removed;

FIGURE 3 is a vertical section taken along the line 3-3 of FIG. 1;

FIGURE 4 is a transverse section taken along the line 4--4 of FIG. 2;

FIGURE 5 is a side elevation of a modification;

FIGURE 6 is a plan of the structure shown in FIG. 5, except with one thumb nut removed;

FIGURE 7 is a transverse section taken along line 77 of FIG. 5; and

FIGURE 8 is a plan of the base of the FIG. 5 embodiment.

The injector is shown in the drawings as applied to a hypodermic syringe having a barrel 10, a needle 12, and a plunger 14. The injector comprises a guide 16 for the barrel 10, and an abutment 18 to engage the body of a patient. The abutment has an aperture 20 for passage therethrough of the needle 12, as the barrel travels along the guide 16. The guide 16 and the abutment 18 are constructed of heat absorptive material of sufficient mass to materially desensitize the area contacted by the abutment 18 against the pain of the needle 12.

In the form shown in FIGS. 1 to 4, the guide 16 is preferably a thick-walled tube of aluminum, having a groove 22 receiving the barrel 10, and forming an observation window for the scale of the syringe. The end of this tube forms an observation window which permits the patient to observe the syringe scale and other parts of the syringe, thus the injection of the medicament and withdrawal of the needle may then be made in the normal manner.

The principal outside diameter of the syringe barrel 10 is only slightly smaller than the inside diameter of the guide 16. This results in reasonably straight line motion of the needle 12 as it is being inserted into the body of the patient, which minimizes the discomfort associated with the insertion of the needle 12 as compared to the hooked motion which frequently results from'manual insertion of the needle without the aid of an injector. In order to provide reasonably straight line motion, the length of the guide 16 should be more than half the length of the syringe barrel.

Another advantage of the guide 16 is that the fear by the patient is alleviated, and less courage is needed to insert the needle 12 into the body of the patient when using the guide 16 than without it. If the guide 16 is cooled by being placed in a freezer, it should be covered with aluminum foil or other food wrapping material to prevent frost accumulation.

The guide shown in FIGS. 1 to 4 is very economical to manufacture and may be made with very inexpensive tooling.

Thus it is generally impractical for the patient to selfadminister the required medicament into an arm, since only one hand would be available. However, the spring loaded or automatic injector shown in FIGS. 5 through 8 can be used with only one hand, thus permitting a patient to self-administer medicaments into the arm of the other hand.

In this automatic form, the guide for the barrel 10 is a flat length of sheet metal forming a base 24 having a longitudinal slot 26, and the patient contacting abutment is an inclined flange 28 having a needle receiving aperture 30. The injector is provided with a holder 32 for the syringe barrel 10, the holder having slides 34 and 36 movable along the guide slot 26.

Preferably the holder 32 comprises a strip of sheet metal folded to form the ends thereof into parallel jaws 38 receiving the barrel 10 and clamped by screws 40 with thumb nuts 42. The jaws 38 are thereby spaced apart to form a socket for the barrel and an observation window of a length of more than half the length of said barrel. The slides 34 and 36 are preferably formed by guide washers 44 and retaining washers 46 secured to the holder 32 by rivets 48.

A spring 50 urges the holder 32 forward along the guide slot 26. Preferably the spring is hooked through holes 52 in the base 24, and through hole 54 in the holder 32. The slot 26 has an open rear end, and the rearmost slide 34 is movable therethrough against the action of the spring 50 into lateral cocked position against the stop 56.

In operation, the cooling flange 28 or the entire injector'is'cooled below ambiefit'temperamre aindthesyring'' filled as before described. The principal outside diameter of the barrel is placed between the jaws 38 of syringe holder 32 and on the screw "or screws 40 as illustrated in FIG. 7. The forward portion of the needle hub is positioned approximately flush with the back of the cooling flange 28. The thumb nut or nuts 42 are then tightened so that the syringe is firmly held by jaws 38.

The injector is placed in the cocked position by the patient grasping the syringe holder 32 and pulling upward to bring the slide-34 out of the slot 26, and then to the right so that the rear guide washer 44 is resting on the rear of the' base 24. Stop 56 prevents excessive side movement of the rear guide washer 44. f

' After repeated usage, the patient is able to very'quickly load the syringe in the injector, thus the cooling flange 28 will still beat a temperature 'well below ambient temperature.

'The injector is triggered by the patient-pushing the syringe holder 32 toward the guide slot 26 until the rear guide washer 44 is pushed off the rear of base 24 into the guide Slot. This results in the propelling spring 50 pulling the syringe holder 32' toward the patient contacting face of flange 28 with the washer of rear slide 34 and the Washer of front slide 36 moving down in the slot 26 until the front guide washer strikes the front end of the guide slot 26.

The injector shown in FIGS: 5 through 8 is economical to manufacture and may be made with inexpensive tooling. All of the parts, except the base 24 and the syringe holder 32, may be purchased as stock commercial parts at "low cost without tooling charges.

With reference to the abutment 18 or the patient contacting face of flange 28, it was discovered that even with the aperture or the opening there is direct cooling adjacent to but not on the injection site, which results in a reduction of the discomfort associated With the insertion of the needle 12 into the body of the patient. There are important advantages to having the aperture 20 or the opening 30. The abutment 18 or patient contacting face of the flange 28 does not contact the injection site, thus there is no possibility of contaminating the injection site with a non-sterile contacting face. It is not necessary to remove anything to permit the needle to be inserted into the patient; The needle can be inserted while the contacting face is still in contact, thus producing maximum cooling effect and simplifying usage by the patient.

In order to significantly cool the body adjacent to the injection site, it was discovered that the wall thickness of the abutment 18 or the flange 28 should be more than inch. Increasing the wall thickness provides increased cooling. It is also desirable to use a material for the abutment or the cooling flange 28 having a reasonably high thermal conductivity, such as aluminum, copper or steel, although other materials may be used.

Due to the advantages of lower cos t ar 1d s irn pl icity guide portion of the injector be integrally connected. A further advantage of the injectors shown is that the injection site may be moreaccurately located as compared to manual insertion ofthefneedle. a

What isclaimedisi I. Injector for asyringe having a barrel and a hypodermic needle for injecting a patient, and comprising only two special parts", consisting of a relatively stationary base part and a relatively movable part;

said base part comprising a guide for said barrel consisting of a substantially rectangular length of sheet metal with aiiat portion'having'a cen'tfal longitudinal slot extending from an open rear end to nearthe center thereof and an integral flange at the opposite end having a needle receiving aperture; 'said flange being constructed of high heat absorptive material and having flat portions on each side of said aperture each of a greater width than said slot to afford sufficient mass to materially desensitize the area contacted thereby against the pain of said ne'edlei said movable part comprising a holder for the syringe having slides movable along said slot comprising a strip of sheet metal folded to form the ends thereof into parallel jaws for receiving the syringe barrel; said slides being secured to said holder strip of sheet metal between said folded jaws; and a spring hooked through holes in the guide metal and through a hole in said holder to urge it forward along the central guide Slot; the rearmost slide being movable back out through the open rear end of said guide slot and free thereof so as to be moved laterally onto the adjacent metal'of the rear of the stationary guide part into cocked position. 2. Injector as claimed in claim 1, in which said flat portions are of a greater width than said barrel.

3 Injector as claimed in claim 1, in which the mass of said flat portions is greater than that required for structural purposes.

1 References Cited UNITED STATES PATENTS 1,671,655 5/1928 Schneider 308-38 1,921,034 8/1933 LaMarche 128-2182 1,991,103 2/1939, King 128218.2 2,664,086 12/1953 Transue 128218.2 2,674,246 4/1954 Bower 128-215 2,746,264 5/1956 Keyes 128-339 3,198,467 8/1965 Elfsten' 248316 u v FOREIGN PATENTS 1,107,099 12/ 1955 France.

RICHARDA. GAUDET, Primary Examiner. W. 7E. KAMM, D. L. BAKER, Assistant Exanziners. 

